/*
 * LocaleFilter.java
 *
 *
 */



package com.myapp.web;

//~--- non-JDK imports --------------------------------------------------------

import org.apache.struts.Globals;

//~--- JDK imports ------------------------------------------------------------

import java.io.*;

import java.net.*;

import java.text.*;

import java.util.*;

import javax.servlet.*;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.*;

/**
 *
 * @author  hantsy
 * @version
 */
public class LocaleFilter implements Filter {
    private final static String  LOCALE_COUNTRY_KEY  = "country";
    private final static String  LOCALE_LANGUAGE_KEY = "language";
    private static final boolean debug               = true;

    // The filter configuration object we are associated with.  If
    // this value is null, this filter instance is not currently
    // configured.
    private FilterConfig filterConfig = null;

    public LocaleFilter() {}

    private void doBeforeProcessing(ServletRequest req, ServletResponse response) throws IOException, ServletException {
        if (debug) {
            log("LocaleFilter:DoBeforeProcessing");
        }

        // Extract attributes we will need
        HttpServletRequest request  = (HttpServletRequest) req;
        HttpSession        session  = request.getSession();
        Locale             locale   = (Locale) session.getAttribute(Globals.LOCALE_KEY);
        String             language = request.getParameter(LOCALE_LANGUAGE_KEY);
        String             country  = request.getParameter(LOCALE_COUNTRY_KEY);

        if (((language != null) && (language.length() > 0)) && ((country != null) && (country.length() > 0))) {
            locale = new java.util.Locale(language, country);
        } else if ((language != null) && (language.length() > 0)) {
            locale = new java.util.Locale(language, "");
        }

        if (locale == null) {
            locale = locale.getDefault();
        }

        log("current locale is #" + locale);
        session.setAttribute(Globals.LOCALE_KEY, locale);

        //
        // Write code here to process the request and/or response before
        // the rest of the filter chain is invoked.
        //
        //
        // For example, a logging filter might log items on the request object,
        // such as the parameters.
        //

        /*
         * for (Enumeration en = request.getParameterNames(); en.hasMoreElements(); ) {
         *    String name = (String)en.nextElement();
         *    String values[] = request.getParameterValues(name);
         *    int n = values.length;
         *    StringBuffer buf = new StringBuffer();
         *    buf.append(name);
         *    buf.append("=");
         *    for(int i=0; i < n; i++) {
         *        buf.append(values[i]);
         *        if (i < n-1)
         *            buf.append(",");
         *    }
         *    log(buf.toString());
         * }
         */
    }

    private void doAfterProcessing(ServletRequest request, ServletResponse response)
            throws IOException, ServletException {
        if (debug) {
            log("LocaleFilter:DoAfterProcessing");
        }

        //
        // Write code here to process the request and/or response after
        // the rest of the filter chain is invoked.
        //

        //
        // For example, a logging filter might log the attributes on the
        // request object after the request has been processed.
        //

        /*
         * for (Enumeration en = request.getAttributeNames(); en.hasMoreElements(); ) {
         *   String name = (String)en.nextElement();
         *   Object value = request.getAttribute(name);
         *   log("attribute: " + name + "=" + value.toString());
         *
         * }
         */

        //
        //
        // For example, a filter might append something to the response.
        //

        /*
         * PrintWriter respOut = new PrintWriter(response.getWriter());
         * respOut.println("<P><B>This has been appended by an intrusive filter.</B>");
         */
    }

    /**
     *
     * @param request The servlet request we are processing
     * @param result The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        if (debug) {
            log("LocaleFilter:doFilter()");
        }

        doBeforeProcessing(request, response);

        Throwable problem = null;

        try {
            chain.doFilter(request, response);
        } catch (Throwable t) {

            //
            // If an exception is thrown somewhere down the filter chain,
            // we still want to execute our after processing, and then
            // rethrow the problem after that.
            //
            problem = t;
            t.printStackTrace();
        }

        doAfterProcessing(request, response);

        //
        // If there was a problem, we want to rethrow it if it is
        // a known type, otherwise log it.
        //
        if (problem != null) {
            if (problem instanceof ServletException) {
                throw(ServletException) problem;
            }

            if (problem instanceof IOException) {
                throw(IOException) problem;
            }

            sendProcessingError(problem, response);
        }
    }

    /**
     * Return the filter configuration object for this filter.
     */
    public FilterConfig getFilterConfig() {
        return (this.filterConfig);
    }

    /**
     * Set the filter configuration object for this filter.
     *
     * @param filterConfig The filter configuration object
     */
    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
    }

    /**
     * Destroy method for this filter
     *
     */
    public void destroy() {}

    /**
     * Init method for this filter
     *
     */
    public void init(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;

        if (filterConfig != null) {
            if (debug) {
                log("LocaleFilter:Initializing filter");
            }
        }
    }

    /**
     * Return a String representation of this object.
     */
    public String toString() {
        if (filterConfig == null) {
            return ("LocaleFilter()");
        }

        StringBuffer sb = new StringBuffer("LocaleFilter(");

        sb.append(filterConfig);
        sb.append(")");

        return (sb.toString());
    }

    private void sendProcessingError(Throwable t, ServletResponse response) {
        String stackTrace = getStackTrace(t);

        if ((stackTrace != null) &&!stackTrace.equals("")) {
            try {
                response.setContentType("text/html");

                PrintStream ps = new PrintStream(response.getOutputStream());
                PrintWriter pw = new PrintWriter(ps);

                pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n");    // NOI18N

                // PENDING! Localize this for next official release
                pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");
                pw.print(stackTrace);
                pw.print("</pre></body>\n</html>");    // NOI18N
                pw.close();
                ps.close();
                response.getOutputStream().close();;
            } catch (Exception ex) {}
        } else {
            try {
                PrintStream ps = new PrintStream(response.getOutputStream());

                t.printStackTrace(ps);
                ps.close();
                response.getOutputStream().close();;
            } catch (Exception ex) {}
        }
    }

    public static String getStackTrace(Throwable t) {
        String stackTrace = null;

        try {
            StringWriter sw = new StringWriter();
            PrintWriter  pw = new PrintWriter(sw);

            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        } catch (Exception ex) {}

        return stackTrace;
    }

    public void log(String msg) {
        filterConfig.getServletContext().log(msg);
    }
}
